Serious running problems

[tw3ak]

Hiya, having read the forum for many months, i thought i'd register and pick your brains.

I've owned an '84 1.9 (Watercooled) T25 for nearly 2 years now and there's been a problem with it since I bought it, but has steadily got worse.

First time it did it was on the way home from picking it up, approximatly 50 miles into the drive. It juddered violently, but backing off the accelerator did the trick.

Never happened until a couple of months later on a return leg of a 250 mile drive, but this time when overtaking on a duel carriageway. Juddered badly again, and my speed plumeted from 65 to about 35/40. Backing off the accelerator worked again, but even trying to pick up the pace slightly caused it to do the same. Stopped, van wouldnt start for about 10 minutes. Set off again, fine for another 20 or so minutes.

Having been put off by it, i've not really used it in the last year, but with summer coming, i'm wanting to get it going.

As it stands, it won't do any sort of slight incline, or accelerating more than a snails pace.

What I *think* could be causing it is a rusty fuel tank? It's quite bad, and when i've drained it theres loads of little flecks of rust sitting at the bottom of the petrol. Fuel filter was full of the stuff, but i've changed it (the filter) and still no go.

Do you think there could be crap stuck in the fuel lines and would it be fixable by either blowing them through (?) or just changing them? That, and is changing them easy enough ? I had a peer last month and didn't see any major difficulties.

Sorry for the long post, just trying to get a good idea as to if im going in the right direction, or would a new tank be a waste of money? Would like to change the lines first if it's worth a try ...

[BeaKiE]

It could be a number of things but most engine problems are caused by either a lack of fuel or a poor spark.

Have you tired cleaning the spark plugs and checking the ignition timing?

It could be down to a blocked fuel pipe, or it could be a problem with the fuel pump, coil, or ignition leads.

I tend to work by replacing the cheapest bits first if I can't see an obvious problem.

Rich

[syncroand101]

Have you tried seeing how much fuel the pump is pulling through!?

Taking the pipe that feeds the carb off putting it in a jar (to catch any fuel) and turn it over..? Could just be new fuel pump bout £45.

But then again - could be number of other things!

[stuckin88]

Have you cleaned out the plastic air intake trunking fixed on top of carb.? this gets full of crud from breather, bits of which fall into carb & block jets temporaily--also detach fuel line at both ends & squirt a squeezy bottle of petrol thru it---& get an aerosol of Wynns carburettor cleaner from Halfords & squirt thru carb--

[TYG]

check ya tyres

[Cruz]

mine once did that when i'd run the tank right down......crap in the carb

[tw3ak]

Carb's been off numerous times, jets blown through no bother.

Plugs, leads, dizzy cap etc were changed not so long back, but problem hasn't changed. Timing has never been altered since I bought it, but I would have thought that as it's got progressivly worse without the timing being adjusted it wouldn't be that?

When testing the fuel pump, how much is meant to come through? I'll do that tomorrow see if I get any further.

Carb cleaner has been put through numerous times, and again, jets are all clean. Air intake, clean as a whistle.

I'll try squirting a bottle of petrol through it, see if anything gets shifted.

[Slackbladder]

whilst there, it might be worth checking your gearbox oil too; as this is often over looked.... personally speaking it was at any rate; but only for about... 4 YEARS!!!! Al fine now though

[ghost123uk]

Funny no-one has mentioned carb icing yet ?

The big air inlet pipes to the air filter get fed by warm air when the weather is cold, via a heat exchanger on the r/h exhaust pipe.

If the thermo switch ( mechanical I believe ? ) is stuck or the pipes have come off ( mine did ) then you can end up with icing inside the carb ( due to the rapid air pressure drop in there )

Worth a check ( does it only do it on cold days ? )

Otherwise rust in the tank filter / filters causing fuel starvation under high demand conditions.

[trundletruc]

My 84 DG camper has shown the symptoms you write about. It is usually the jets on the top of the carb that are the problem. Somehow? bits get in the top of them. Two of the jets are easy to clean out but two of them are part of the casting and the only way I get them cleared is to take the carb apart or as a temporary measure blow through a small tube.

While you are at it replace all the rubber bits in the carb in case there is a leak of air of petrol and set it up as the Haynes manual.

[tw3ak]

Cheers for the replies guys and gals.

A new fuel filter has been fitted and it *IS* the correct way around incase anyone mentions it Checked for a vacuum aswell, definatly not. No air rushing in, and is a vacuum even possible if theres a hole at the top of the tank?

Carb icing has always been a possibility, but it's done it in the height of summer aswell, and one of my local mechanics said it'd need to be way colder.

Everytime i've cleared the jets in the carb, i've taken the whole thing apart just to get at every one.

The gasket between the top and bottom half of the carb isn't the best though. Didn't think it would lead to running problems as bad as this, but does anyone know where I can get one? I've tried the typical gunky stuff from a motorfactors to make your own, but my level of skill with it is poor, and i've had bits come off and jam the jets.

I'll need to see what the weather will be like on Sunday (next time i'm near the van - parked at my folks atm), so keep close to a computer, i'll need your assistance

Thanks again!

[TechtroT25]

GSF do carb rebuild kits i got one from a local motorfactors for about £35 comes with all gaskets diaghrams jets etc as someone else said clean the carb then clean again and again